Grade 8 Physical and Life Sciences Review

Fill-in-the-blank flashcards reviewing atomic models, subatomic particles, atomic structure, photosynthesis, cellular respiration, and environmental factors on cellular processes.

To fix a Sodium atom model with 2 beads on the inner ring and 9 on the middle ring, Mateo should move 1 bead from the middle ring to a new __________ ring.

outer

Joy should complete her 3D model of an Aluminum atom (13 electrons) with 2 buttons on the first loop and 8 on the second loop by placing the remaining 3 buttons on a new __________ loop.

third

In Lito's paper plate model of Phosphorus (Atomic Number = 15, Mass Number = 31), the center nucleus contains 15 red dots for protons and 16 blue dots for neutrons, with 15 yellow dots representing __________ orbiting outside.

electrons

The nucleus contains almost the entire mass of an atom because protons and neutrons both have a relative mass of 1 amu, while electrons outside have __________ mass.

negligible

When an atom loses an electron, it becomes __________ charged.

positively

Bombarding uranium with neutrons to split it into an atom with 56 protons and another with 36 protons demonstrates the creation of a new element because the number of __________ is altered.

protons

Bohr's model explained why electrons do not spiral into the nucleus by proposing that electrons move within specific __________ levels around the nucleus.

energy

Each chemical element is uniquely identified by its number of protons, which is known as its __________ number.

atomic

Protons and neutrons are found in the nucleus, while electrons move in electron __________ around the nucleus.

shells

Isotopes are defined as atoms of the same element that have different numbers of __________.

neutrons

If Maria draws a positively charged Sodium ion ($Na^+$) with 11 protons and 12 neutrons, she should draw __________ electrons orbiting the nucleus.

10

In 1913, Niels Bohr modified Rutherford's atomic model by placing electrons in specific, fixed __________ levels around the nucleus.

energy

Rutherford's Nuclear Model concluded that an atom has a small, dense, positively charged nucleus and that the volume of an atom consists mostly of __________ space.

empty

Dalton's concept of an indivisible atom was disproved by the identification of __________ inside the atom.

electrons

While Bohr showed electrons in fixed energy levels, Erwin Schrödinger's model showed regions where electrons are __________ likely to be found.

most

A leaf cell has chloroplasts and mitochondria while a muscle cell has mitochondria but no chloroplasts, meaning both cells perform cellular respiration, but only the leaf cell can perform __________.

photosynthesis

Increasing light intensity increases the rate of photosynthesis up to a certain point because light provides __________ to drive photosynthesis reactions.

energy

If a plant is kept in complete darkness, the process of __________ will stop.

photosynthesis

Green plants have a low rate of photosynthesis under green light because green light is __________ by chlorophyll.

reflected

When there is not enough oxygen available, the rate of cellular respiration __________.

decreases

J.J. Thomson used the deflection of cathode rays by __________ and magnetic fields as proof to confirm the charge of the electron.

electric

Erwin Schrödinger described the atom as having electrons that occupy __________ regions where their location cannot be predicted.

cloud-like

During an intense summer heat wave, higher temperatures cause the rate of evaporation to __________ up.

speed

Covering the stomata reduces the rate of photosynthesis because carbon dioxide cannot __________ the leaf.

enter

In plants, both photosynthesis and __________ occur.

respiration

When deep standing water from a storm in Norala blocks oxygen from corn roots, the roots will produce less __________ for their activities.

energy

When sealed plastic bags of live bangus fry are delayed on the way to General Santos City, oxygen levels decrease while carbon dioxide levels __________.

increase

In a plant cell diagram, the cell part mainly responsible for photosynthesis is the __________.

chloroplast

The cell organelle where the process of cellular respiration mainly occurs is the __________.

mitochondrion